The present invention relates to microswitches and particularly optical micromirror switches.
An example of a flexureless micromirror device known in the prior art is shown in U.S. Pat. No. 6,040,935 (Michalicek). (The entire contents of this patent and all other patents, other publications and applications mentioned anywhere in this disclosure are hereby incorporated by reference.) The ""935 patent discloses a flexureless micromirror assembly wherein the micromirror surface is attached to one or more support columns. These support columns are anchored to the structural assembly of the device by a flexible locking joint. Thereby, the mirror surface is free to move about the joint and the mirror surface can be electronically switched between multiple stable positions. Although such a device operates without the need to flex or bend any mirror surface through elastic bending or through piezoelectric flexing, its construction is complex and expensive to carry out.
U.S. Pat. No. 5,583,688 (Hornbeck) and U.S. Pat. No. 5,650,881 (Hornbeck) are examples of other prior art patents.
Accordingly, it is an object of the invention to provide a simplified construction and operation of a flexureless magnetic micromirror. This is done according to a preferred embodiment by hinging the micromirror over a centrally positioned pin or cone. The mirror is secured from moving laterally by a conical depression in the underside of the mirror and secured against lifting off of the mirror by engagement of the capillary force of a suitable liquid sandwiched between the mirror and the corresponding substrate mounted on a base. A plurality of microelectromagnets are is positioned directly below the periphery of the mirror. When these microelectromagnets are electronically activated they attract the corresponding metallic edge of the magnetic mirror. The central support pins height governs the tilt angle of the mirror, reflecting the incident light beam to become the reflected light beam. The simplicity of this invention allows the simultaneous assembly of large arrays of these micromirrors of high precision and minimal cost compared with the optical switches known in the prior art. Additionally, very high switching speeds are possible with this invention due to the absence of flexing resistances, initial retardation and mechanical friction. The tilt angle of the micromirror is preferably between sixteen and twenty degrees. The magnetic mirrors can be produced relatively inexpensively by manufacturing them of composites of powdered fillers and polymer matrix where the filler material is a magnetic material. The manufacturing process, including the production of the mirror surface, is described in application Ser. No. 09/345,813, filed Jul. 2, 1999.
Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the foregoing description taken in conjunction with the accompanying drawings.